The present disclosure relates to a battery load drive system, and more particularly, to a battery load drive system for preparing for a surge current generated by a capacitor when a battery is coupled to a battery using a path for reducing current additionally provided in an existing path.
Generally, a device (load) using a motor receives electrical energy to couple with a charged battery and converts the charged electrical energy of the coupled battery into a mechanical energy through the motor in the load.
However, the high-frequency current is induced in an electric wire by the switch (relay, IGBT, FET, etc.) of the power semiconductor, and this high frequency current causes the battery to overload and generate noise in the electric wire.
As a solution to this problem, a capacitor is mounted in the load to prevent the high frequency switching current from being discharged to the outside.
Although the capacitors differ depending on the power used, a high capacity is usually used to reduce the ripple current generated during the drive.
However, when the capacitor is directly coupled to the battery without a separate circuit, a surge (inrush) current is momentarily generated in the device (load).
The surge current has a large current value as the capacity of the capacitor increases. If such a surge current flows through the circuit, there is a risk that the life of the capacitor is reduced due to the large current and the peripheral device is destroyed so that a fire is generated.
A conventional technique for preventing such surge current generation will be described in detail with reference to FIG. 1.
FIG. 1 is a circuit diagram of a conventional surge current generation prevention circuit.
Referring to FIG. 1, conventionally, a second path having a precharge resistance is formed separately in addition to a first path for supplying a current from a battery to a load, so that when the battery is coupled to the load, by allowing the current flowing from the battery through the second path to flow in the precharge resistor to reduce the current.
However, such a method has a large resistance depending on the amount of current, and a large resistance takes up a lot of space.
Also, since the required capacitor size is different according to each load, it is difficult to apply various resistance values.
Therefore, in order to improve the reliability of the product due to the safe drive and to be applicable to the various loads, it is necessary to provide various sizes of currents to prevent the surge current generated when the battery is coupled to the load.